Grinding block



' C. A. YEHLE.

GRINDING BLOCK.

APPLICATION FILED MAY 12. 1920.

Patented Feb. 7, 1922.

IrvvswroR 6. a. B

1' OFFICE.

CHARLES A. YEHLE, SYRACUSE, NEW YORK.

GRINDING BLOCK.

Specification of Letters Patent. 7 Patented Feb. 7, 1922.

' Application filed May 12, 1920. Serial No. 880,898.

To all whom it may comm:

Be it known that I, Gimme A. YEHLE, of Syracuse, in the cou nt of Onondaga, in the State of New York, ave invented new and useful Improvements in Grinding Blocks, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to'certain improvements in rinding blocks adapted to be magnetically eld upon a magnetic bed or car riage, and provided with means for receiving and supporting a thread-cutting tool or analogous implement for grinding the cutting edges thereof as the carriage is moved back and forth across the face of a rotary grinder.

These tools are used for cutting right and left hand threads, and their cutting edges are, therefore, ground on four sides, viz: the top side, opposite upright sides, and in some instances the point, or extreme cutting edge, depending upon the kind of thread desired, the opposite upright sides being usually under-cut or slightly beveled towards the heel of the tool for clearance purposes, it being understood that the side facin the direction of movement of the tool holder is. usually ground to a greater angle than that of the opposite side owing to the inclination of the thread.

The object of my invention is to provide a block of magnetizable m'aterial with supporting faces adapted to rest upon the bed in such manner that all four faces of the tool may be ground to the desired angle for cutting either right or left hand threads without removing the tool from the block, or in other words permitting four sides of the tool to be ground to the desired angle for right hand threads with one adjustment, and the same number of sides to be ground by simply reversing the tool in the same block.

Another object is to utilize the same opening in the block for receiving tools of different sizes by providing one of the Walls of said opening with stepped seats against which the tools of difierent sizes" may be held by a single set screw.

Other objects and uses relating to specific parts of the grinding block will be-brought out in the following description:

In the drawings:

Figure 1 is a side elevation of my improved grinding block with the tool therein iii.

in position for grinding the tool'to cut right hand threads, the dotted line at the bottom representing the magnetic bedor carriage upon which the lower face of the block rests when used for grinding theupper face of the'cutting edge of the tool, a portion of the grinder-being also indicated by dotted lines. Figure 2 is a front face view of the same plockl with the tool therein, as shown in igure 3 is a side elevation, partly in sectron, of the same block reversed end for end in the direction of extension of the tool with the tool therein adapted to be ground for cutting left hand threads.

Figure 4 is a front side view of the block with the tool therein, as shown in Figs. 1 and 2, supported upon one of its lengthwise sides for grinding one of the upright sides of the tool to cut right hand threads.

Figure '5 is an end view of the block with the tool therein as shown in Figure 4.

Figure 6 is another front side view with the tool therein as shown in Fig. 4, except that a different side is engaged with the bed or carriage, and that the block is reversed end for end from the position shown in 4. 'gure 7 is an end view of the block in the position shown in Fig. 6, in which the grinding angle is greater than that produced when the block is in the position shown in Figures 4 and 5.

Fig. 8 is a front. sideview of the same block in position for grinding one of the upright sides of the tool to cut left hand threads.

Fig. 9 is an end view of the block Withjhe tool therein as shown i-n Figure 8.

Figure 10 is a front face view of the block as shown in Fig. 8, except that a different" side thereof is supported upon the fected by supporting different sides of the block upon the carriage, while in Figs. 3, 8, 9,

10 and 11, the tool is reversed in the block both endwise and transversely to permit its different sides to be ground for cutting left hand threads without removing the tool from the block, by simply supporting different sides of the block fiatwise upon the carriage.

The grinding block 1 is. adapted to be supported upon an electrically magnetized bed or carriage A- shown by dotted lines in the several figures, and is'preferabl made in one piece of magnetic metal, suc as machine steel, the bearin surfaces of which may be hardened to re uce wear and assure greater permanency of their relatlve an ular relation.

s illustrated, relatively small portions of zones at both ends of the block are hexagonal and hardened, while the main body may remain unhardened, and is preferably of less cross-sectional area than the end zones, or heads, so that all portions thereof will lie within the planes of the several faces or edges of the end heads, to allow said faces to be easily milled to the desired angles, and also to assure auniform bearing of those faces or edges throughout their areas upon the supporting bed or carriage, as will be I hereinafter more fully described.

The end faces, as 2- and 3- of the heads are flat and disposed in parallel planes, while the main body to which the end heads are integrally united, is also hexagonal in cross-section and is provided with a transverse tool opening 4l which extends cen trally therethrough from side toside in a plane substantially parallel with and midway between the end faces 2- and 3-, and is preferably rectangular in cross-section, with two of its {opposite sidewalls disposed in planes at substantially right angles to the end faces -2 and -3-, and

its other two side walls substantially parallel with said faces for receiving a tool B- of similar cross sect'on.

This block is provided ith a threaded opening 5 extending inwardly from one of its end faces as 3' to the adjacent side of the tool opening --41-- at substantially right angles thereto for receiving a set screw 6- by which the tool B' is held in operative position in the block during the grinding operation. I

Theside of the opening 4 opposite the set screw 6 is provided with stepped hearings, or seats -7 for receiving tools of different sizes and against which each is held by theset screw --6 when adjusted in the block for grinding.

The face of the grinding element C'-- shown by dotted lines in Figs. 1, 3, 5, 7, 9 and 11 rotates in a substantially horizontal plane. parallel with the surface of the bed or carriage -A, either the bed or grinder being adjustable vertically to bring the tool into contact with the grinding surface when its holding block is supported in different positions on the carriage.

As previously stated, the block is hexagonal in cross-section, two of its lengthwise sides, as 8- and 9-, at opposite ends of the opening -4- being disposed in parallel planes at an angle of approximately 15 degrees to the planes of the end faces 2-- and --3--, as shown more clearly in Figures 1 and 3, and, therefore, at the same angle to the plane of the tool when inserted in the opening 4- which is parallel with the end faces 2- and -3-, the cutting end of the tool -being adjusted to project some distance beyond one of said faces, as -9, for grinding the same to cut right hand threads, and is readjusted to project some distance beyond the other face, as 8- of the block, for grinding its several faces to cut left hand threads, in which case the block would simply be inverted from the position shown in Figure -1- to the position shown in Figure 3.

When the block is standing on either of its end faces, as for example on the end face 2-, with either of the lengthwise faces 8- or 9- at right angles to theeye, as shown in Figure 2, it will assume a position at an angle of substantially five degrees from a vertical plane, or in other words, its axis will be at an angle of 'substantially five degrees to a vertical plane for the purpose hereinafter described.

Two of the other lengthwise sides, as -.r10- and 11- are disposed in planes at an angle of, in this instance, approximately 60 degrees to each other so as to converge toward one of the previously named length.- wise sides, as -8, or at an angle of approximately 30 degrees to a lengthwise plane passing through the axis of the tool opening -4, or tool B therein when the latter is adjusted in the opening for grinding to cut right land threads.

The two remaining lengthwise sides, as 12-- and 13- of the hexagonal block are also disposed in planes at an angle of substantially 60 degrees to each other, or 30 degrees to that of the tool B and its opening 4- and are adapted to rest upon the surface of the bed or carriage --A for grinding opposite sides of the tool at angles of approximately. 30 degrees to its longitudinal center to cut left hand threads.

From the foregoing description, it will be seen that the sides 10- and 13- are directly opposite each other and disposed in parallel planes, while the sides 11 and -12- will also be opposite each other and disposed in parallel planes, each of said sides constituting a substantially flat face adapted to rest upon the surface of the bed or carriage A- with the tool therein for grinding opposite faces of the cutting. edge of the tool to the desired angle at which the threads are to be cut.

- In order that the opposite faces of the tool may be under-cut from the cutting edge toward the heel to provide for the necessary clearance of the tool in the work, the end faces -2 and 3 are disposed at an angle of substantially five degrees to the planes of the lengthwise sides -l0 and 13-- respectively, as shown in Figures 4 and 10 are also disposed in planes at an angle of substantially 10 degrees to those of the lengthwise faces 11 and -12-, respectively, so as to grind the advancing face of the. cutting edge of the tool at a steeper angle or greater bevel than the opposite face to clear the incline of the thread as the latter is being cut.

Operation.

Assuming now that it is desired to grind the tool for cutting right hand threads, in which case the tool is secured by the set screw 6- in the opening 4 with its cutting end projecting beyond the lengthwise bearing face -9, as shown in Figures 1, 2, 4, 5, 6, and 7 the tool supporting block may then be placed with its end face -2 resting upon the magnetic bed or table A and magnetically held in position while the carriage is moved back and forth across the underside of the grinder ---C- for grinding the upper face of the tool, as shown in Figures 1- and --2-, the face thus ground being parallel with the end face 2 and also square with the tool which is then parallel both longitudinally and transversely with the surface of the bed plate or carriage A.- The block with the tool therein may then be adjusted with its lengthwise side lO resting upon the carriage, A and moved beneath the grinder -C to grind the cutting face at an angle substantially 30 degrees to the axis of the tool, and also to give it a clearance of approximately 5 degrees from the cutting edge to the cutting end.

The block with the tool therein may then be turned over upon its other side 11-, or to position shown in Figure 7, and again moved across the underside of the grinder to grind the opposite face of the tool at the same angle, but with slightly greater clearance, in this instance 10 degrees, to avoid friction between the head of the tool and the right hand thread which is then being cut and which inclines in the same direction.

In case it should be necessary to grind the edge of the tool, the block may be supported with its face 8 resting upon the carriage A- and moved under the grinder C to grind the edge, as b-, parallel with the face 8-, or with a clearance of approximately 15 degrees between the cutting point and heel of the cutting edge.

' Assuming again that" it is desired to grind the tool for cutting left hand threads, said tool is withdrawn from the side -9- of the block and reinserted in an inverted position in the opposite side 8 of said block with its cutting end projecting some distance beyond the side 8, as shown in Figures 3, 8, 9, 10 and 11. In order to grind the upper face of the tool, the block is placed with its end face 3 resting upon the carriage 8 and is then moved across the underside of the grinder C to bring the upper face of the tool into contact therewith, as shown in Figure 3-', after which it is placed with its side 11 upon the carriage -A and again moved across the underside of the grinder to grind one side of the tool ,to the desired angle, as shown in Figures When this operation is completed, the tool is turned over with its side 12 resting upon the carriage -A and is again moved across the underside of the grinder to grind the other faces of the tool to the desired angle, both angles being substantially the same as those ground for cutting right hand threads, the clearance angles being also the same as described in grinding the tool for cutting righthand threads. That is, in F igures 10 and -11- the block is supported for grinding one side of the tool at a five degree angle of clearance, while in Figures 8 and 9, it is shown in position for grinding the tool to a, 10 degree clearance.

What I claim is:

, 1. A one-piece grinding block of hexagonal cross section having its end faces parallel with each other and disposed in planes at an angle to those of each of the sides, said block having two of its sides at opposite sides of its axis parallel with each otherand substantially the same width and.

provided with registering tool openings extending through the block to permit the cut-- ting tool to be inserted in the opening in either side.

2. A one-piece grinding block of hexagonal cross-section having its end faces parallel with each other and disposed in planes at an angle to those of each of the sides, said block having two of its sides at opposite sides of its axis parallel with each other and substantially the same width and provided with registering tool openings extending through the block to permit the cutting tool to be inserted in the opening in either side, and a set screw engaged in a threaded aperture in One end of the block for tightening and loosening the tool in said opening.

3. A one-piece grinding block of hexagonal cross-section having its end faces parallel with each other and disposed in planes at an angle to those of each of the sides, said block having two of its sides at other and substantially opposite sides of its axis parallel with each the same 'Width and provided with registering tool openings extending through the block to permit the cutting tool to be inserted in the opening in either side, relatively short portions of the end of'the block being extended beyond the intermediate portions of the block.

4. A grinding block having both ends hexagonal in cross-section and ot' the same form and area, the intermediate portion of the block being provided with a transverse tool opening extending therethrough from side to side.

5. A grinding block having a transverse I a tool opening therethrough and a threaded opening extending inwardly from one end of the block to the tool opening, the walls of the tool opening opposite the threaded opening hein gradually reduced in width to receive too s of different sizes and a set screw engaged in the threaded opening for tightening and releasing the tool.

In Witness whereof I have hereunto set my hand-this 3d day of May, 1920.

CHARLES A. YEHLE.

Witnesses:

' H. E. CHASE,

ROSE G. CAmRoL. 

